Dry shaving device



T. J MURPHY Feb. 7, 1939.

DRY SHAVING DEVICE Filed Nov. 26, 1934 5 Sheets-Sheet l INVENTOR4 Mus-Y5T. J. MURPHY Feb. 7, 1939.

DRY SHAVING DEVICE Filed Nov. 26, 1954 5 Sheets-Sheet 2 uumummuu mm m mw a 7 a 1.3 my 5 N 15 2 :1 M j BT MH M W HUM n J11. r

F 1? II EQE XIVENTOR ATTORNEYS- F eb. 7, 1939,

T. J MURPHY 46,643

DRY SHAVING DEVICE Filed Nov.- 26, 1954 5 Sheets-Sheet 4 ATTORNEY5 7,1939. T. J. MURPHY DRY SHAVING DEVICE Feb.

Filed Nov. 26, 1934 5 Sheets-Sheet 5 INVEN OR W34 BY W ATTORNEYS.

Patented Feb. 7, 1939 UNITED STATES PATENT OFFICE 13 Claims.

This invention relates to a shaving device, and more particularly to aso-called dry shaver in which the shaving operation is performedmechanically.without the 'use of soap and the like,

and has for an object to provide a device for this purpose which willgive a cleaner and closer shave than devices now generally on the marketand will be capable of cutting'hairs of greater length than similarshavers can do now.

Another object is to provide a shaver of this type which will shaveequally efl'ectively in each of the movements in opposite directions'sothat the device may be operated by moving it back and forth over thesurface to be shaved, two opposed shaving features being provided and soarranged that one operates on moving in one direction and the other onmovement in the opposite direction and each acting as a gauge or guidefor the other to retain it at the proper angle for best cutting and mosteifective operation.

A further object is to provide with this type of shaving apparatus animproved operating mechanism which gives rapid operation and plenty ofpower, and which operates without any make or break devices for theelectric current and therefore will be more reliable in operation andmay be operated indefinitely.

Other objects and advantages will become apparent as the descriptionproceeds. It, however, 30 is to be understood that various modificationsand changes may be employed without departing from the spirit of theinvention and within the scope of the appended claims.

Referring to the accompanying drawings:

35 Fig. 1 is a side elevation of the device on an enlarged scale withone section of the enclosing casing removed and parts broken away tomore clearly show the construction;

Fig. 2 is a transverse vertical section of the easing showing theinternal mechanism in side elevation;

Fig. 34s a transverse section substantially on line 3-3 of Fig. 1;

Fig. 4 is a transverse section substantially on line 4-4 of Fig. 1;

Fig. 5 is a detailed section substantially on line 5-5 of Fig. 1;

Fig. 6 is a top plan view of the operating yoke for transmittingmovement from the power de vice to the cutter;

Fig. 7 is a detailed section thereof substantially on line 1-1 of Figs.2 and 6;

Fig. 8 is an edge elevation of the completed device;

Fig. 9 is a front view thereof;

Fig. 10 is a back view;

Fig. 11 is a side elevation of one of the laminations of the core piece;

Fig. 12 is a partial side elevation and a partial longitudinal centralsection of the cutter head; 5

Fig. 13 is a top plan view thereof;

Fig. 14 is an end view;

Fig. 15 is a transverse section of the cutter portion substantially online i5l 5 of Fig. 13;

Fig. 16 is a side elevation of a cutter head of 10 slightly modifiedconstruction;

Fig. 16a is an end view thereof;

Fig. 1'7 is a view similar to Fig. 1 showing a modified construction;

Fig. 18 is a longitudinal section thereof sub- 15 stantially on linel8-l8 of Fig. 17 but showing certain of the elements in elevation;

Fig. 19 is a rear elevation of the device of Figs.

17 and i8;

Fig. 20 is a transverse section substantially on 20 line 20-20 of Fig.17;

Fig. 21 is a detailed section on line v2l-2l of Fig. 1'7

Fig. 22 is a detailed section substantially on line 22-22 of Fig. 17; 25

Fig. 23 is a plan view of one of the laminations of the core for theoperating device in Fig. 17;

Fig. 24 is a vertical section through a plug-in device for operating theshaver, the section being substantially on line 24-24 of Fig. 25;

Fig. 25 is a longitudinal section substantially on line 25-25 of Fig.29; v Fig. 26 is a side elevation; Fig. 27 is a side elevation at rightangles to Fig. 26;

Fig. 28 is a transverse section through the easing substantially on line28-28{-, of Fig. 24 and showing the enclosed elements intop plan view;

Figs. 29 and 30 are transverse sections substantially on lines 28-29 and30-30 respectively of Fig. 24;

Fig. 31 is a wiring diagram for the electrical apparatus;

Fig. 32 is a wiring diagram for an alternative wiring;

Fig. 33 is a wiring diagram for another modification; and

Fig. 34 is a similar wiring diagram for another modification.

Referring first to Figs. 1 to 16a, the device comprises an enclosingcasing indicated generally at l and comprising two separable sections 2and 3 held together by any suitable means such as transverse screws orbolts 4 extending through one section, as section 3, and threaded intometal inserts, such as indicated at 5 molded into the other section 2 atthe upper end and a short transverse bolt or screw 6 at the oppositeend. This casing may be of any suitable material, but is preferably ofmolded electrical insulating material that is a phenolic condensation orsimilar product, such as Bakelite.

Mounted in and enclosed by this casing is the mechanism for operatingthe shaver which is included in the shaving head indicated as a whole atI and mounted in an offset portion 8 formed in the upper end portion ofthe section 2 of the housing or casing. The shaving head 1 is ofrectangular cross-section and is mounted in a similarly shaped opening 9in the offset 8. It is preferably inclined to the body at an angle ofabout 45", as this seems to be the most convenient angle for the body tobe easily held in the hand during the shaving operation, but I am notlimited to this angle as the head may be located in any position foundmost desirable, and even may not be inclined at all but may extend fromthe end of the casing and be substantially parallel with the axisthereof, if desired, as shown in the modification of Figs. 17 and 18.The shaving head I may be held in the casing by any suitable means, buta convenient way of mounting it is by a pair of set screws l0 threadedinto metal inserts ll molded in the casing, these screws clampingagainst the side of the head and holding it in position. Preferably, theside of the head has slight recesses I2 to receive the ends of the setscrews to more effectively clamp the head in position.

This shaving head is a material advance in the art and is shown more indetail in Figs. 12 to 160. In the form of Figs. 12 to 16 it comprises ametal block or body l3 having a longitudinal slot H in one edge leadingto a longitudinal passage II, which edge is curved as shown at l5. Onthe opposite edges of this slot are a series of narrow guide or guardteeth 6, which are spaced apart by narrow slots for entrance .of thehairs in shaving. Inwardly of these guard teeth is the longitudinalguide passage H, which in this form is substantially circular, in whichis mounted a slidable steel cutter [8. This cutter is mounted toreciprocate back and forth longitudinally of the head in the passage I1and has an eccentric longitudinal passage l9 adjacent its upper edge,with a slot 20 leading from this passage in alignment with the slot I4in the block i3. Leading transversely from the edges of the slot 20 inthe cutter are narrow slots forming the narrow cutting teeth 2| which asthe cutter l8 reciprocates slide back and forth over the undersides ofthe guard teeth 16 and the slots between them, the edges of these teethon the cutter and the block giving a shearing action to cut hairs whichmay enter the slots between the teeth. It will be seen from Fig. 15 thatthe teeth on the cutter i8 increase in thickness back from the points orfree ends of the teeth so that the teeth have additional strength andsupport. Also, the guard or guide teeth on the head l3 taper backwardlyfrom their ends or edges in the same manner giving them good strengthand stiffness. The outer surface may be ground off substantially flat,as indicated at 22, providing a substantially flat surface to engage theskin and also permitting the free edges or ends of the teeth on theopposite sides of the slot It being ground to a very thin edge so as togive a out very close to the surface of the skin and thus a very closeshave.

It will be evident that from this: construction there are two opposedcutting devices extending or facing in opposite directions and spacedfrom each other the width of the slot 14. Each of these cutting devicesincludes a set of guard or guide teeth on the head or body l3 and a setof reciprocating or cutting teeth cooperating therewith, both of whichsets of cutter teeth are on the reciprocating cutter 18. Therefore, asthese cutting devices are held against the surface of the skin and thehead is moved over the surface back and forth in a. directiontransversely of the slot l4, first one cutting device on one side of theslot operates as a shaving device, and then when it is moved in theother direction the other cutting device on the opposite side of theslot operates as a shaving device, and therefore as the shaver is movedback and forth over the surface there is always a shaving device withthe free ends of its guard teeth moving forwardly, which is the propermovement and relation for shaving. It will also be seen that as one ofthe shaving devices is operating forwardly in the cutting direction theother is moving ahead of it and against the surface of the skin, andtherefore formsa guide to always maintain the device which is doing thecutting at the proper angle with relation to the surface of the skin forthe best cutting effect and prevents digging into the skin, and tosecure this proper angle, all the user has to do is to hold the end ofthe cutting head .squarely against the surface of the skin, The passagel9 collects and conducts the cut off hairs from the shaving devices sothey are kept clear at all times.

To secure a cutting effect it is of course necessary that the cutter i8be reciprocated in a direction longitudinally of the slot M, or, thatis, transversely of the guard teeth 16, and immediately back of theguard teeth and be held against the back of these teeth for the propershearing effect. The amount of movement of the cutter should be at leastequal to the distance between the teeth 16, but it maybe several timesthis amount, if desired.

This reciprocating motion of the cutter l8 may be secured in variousways, but in'the present instance I have provided an electricallyoperated reciprocating drive element 23 connected with the cutter 18 bymeans of a drive pin 24. This drive pin 24 is fastened to the cutter H!by any suitable means such as screw threads 25 and projects from thebody 13 at the opposite edge from the cutter l8 where it has a taperedend 26 entering a socket or opening 21 in the operating element 23. Inorder to prevent electrical injury to the user of the device should anyof the electrical contacts become grounded, this opening 21 ispreferably in an electrical insulating bushing 28 carried in the member23. In order to hold the cutter H3 in proper alignment the driving pin24 passes through an opening in a guide plunger 29 mounted forreciprocating movements in a longitudinal passage 30 in body 13, as thiscan be given a good accurate sliding fit. It will be evident that asthis guide plunger is spaced some distance from the cutter considerablewearbetween this guide plunger and the body would permit very littleturning movement of the cutter out of alignment, and as this plunger canbe given an extensive bearing surface in the body l3 it can be usedindefinitely without sufficient wear being caused to have auxobjectionable efiect on the alignment of the cutter. To lighten theguide plunger 29 then the ends sealed with discs 32. To permit propermovement in the body the pin 24 passes through an elongated slot 33.

In the form of Figs. 12 to 15 the body or block i3 is made in one piece,but if preferred, it may be made in two pieces 34 and 35 as shown inFigs. 16 and 16a, the line of separation being preferably substantiallyon the center line of the block and the sections secured together by anysuitable meanssuch as the rivets 36. This construction makes the devicesomewhat easier to manufacture as the two opposite sides of the passagesi1 and 30 can be milled in the two sides of the block, and then whenthese two sides are placed together in alignment these guide passagesare completed. With this arrangement the cutter i8 and the plunger 29need not be circular in cross section but may be square, rectangular orother shape.

The operating device for the cutter as shown in Figs. 1 to 6 comprises alaminated core of good magnetic material, such as soft iron, havingthree connected poles 31, 38 and 39 spaced from each other the properdistance and embraced by the coils 49, 4! and 42 respectively. Extendingover the top of the center pole is an armature 43 of magnetic materialand it is preferably U-shaped so that the opposite end portions 44extend between poles 31 and 39 and 38 and 39, but with sufficientclearance to permit the armature to have the proper reciprocatingmovement. The armature should not come in contact with the pole piecesand therefore resilient live rubber buffers in the form of blocks ordiscs 45 are provided between these arms and one of the pole pieces, inthe present instance between these arms and the center pole 39 so thatthe arms are nearer the outer poles 37 and 38. This armature is carriedby a yoke 46 extending over the top thereof and to which the armature issecured by any suitable means, such as the rivets 41. The opposite endsof this yoke extend outwardly and downwardly as'indicated at 48 inopposite directions over the outer poles 31 and 38 and are connected attheir free ends as by rivets 49 with supporting flexible spring elements50. These flexible spring elements are supported at their lower ends byany suitable means, such as screws 5! on a supporting strap 52 fastenedto the lower ends of the laminated core by means of the rivets 53, whichalso secure these laminations together. This strap 52 should be ofnon-magnetic material as should also the yoke 46. To prevent the yoketurning on the spring supports 50 the free ends thereof are providedwith short flanges 54 engaging the opposite edges of the support 50.These spring supports permit the armature to reciprocate insubstantially a straight line and they have sufficient resiliency tonormally bring the armature back to the central or neutral position whennot acted upon by the magnetic elements. On the opposite side of thecore from the strap 52 may be a supporting strap 55 also secured to thelaminated core by the rivets 53, and this strap is provided with adownwardly extending ear in which may be threaded a supporting screw 56extending through the rear wall of the casing. This effectively mountsthe cores and coils at the lower part of the casing. The yoke may bestiffened at the bends by striking out ribs 48a, and the supportingmembers 58 may also be strengthened by longitudinal ribs 50a strucktherefrom.

The cutter operating element 23 is mounted on the yoke 46 so as toreciprocate with it. For this purpose the yoke is provided with arearwardly extending arm 5? to which one end of the member 23 isconnected by any suitable means, such as the rivets 58. This arrangementgives sufficient length to the arm or member 23 so that it can haveyielding resilient action tending to always press the socket 21 tightlyagainst the tapered end 26 of the operating pin 24. This automaticallycompensates for any wear between the pin and the socket, and it alwaysholds the teeth on the cutter l8 closely against the underside of theguard teeth l6 and automatically compensates for wear between the cutterand the guiding head to give proper cutting action of the cutter.

The upper part of this operating mechanism is securely anchored to thecasing by a screw 59 extending through the center pole 39 and threadedinto a metal insert 60 molded in a lug or boss 6| projecting inwardlyfrom the back wall of the casing section 3 so that the upper end of thecore and associated mechanism are rigidly anchored to the casing. Thecore may also be braced by legs 31 and 38 resting against lugs 61a onthe rear section 3 of the casing. A plate 62 is preferably placedagainst the front of the center core 39 through which this screw 59passes, and at its lower end is provided with an outwardly extendingflange 63 resting on the tops of the coils 40, 4| and 42 to hold them inproper position. The laminations of the core at the poles 3'! and 38 maybe secured together by rivets 64,

The flattened or oval shape of the body makes it easily gripped and heldin the hand of the operator. The cord 65 for the electrical leads to thevarious operating coils preferably extends into the casing at the lowerend thereof and laterally from one edge as shown. The opening into thecasing is preferably provided with ribs 66 to grip the covering on thecord when the casing sections are clamped together to securely hold thecord in position and prevent strain on the cord from pulling the leadwires away or breaking their connections to the coils. The casing may beprovided with an opening 51 on the opposite side in alignment with theopening for the cord 65 to receive the ends of a cord loop 68 wherebythe device may be hung on a hook or any suitable support when not inuse. A metal grip or sleeve 69 may be clamped about the ends of thiscord loop in the casing to prevent its withdrawal through the openingBl.

I now refer to the modification shown in Figs. 17 to 23. It will benoted from the above description that in the form of Figs. 1 to 6 thereclproeating cutter i8 is connected directly to the armature 43 so asto move with it. In .the form shown in Figs. 17 to 22, however, theoperating armature is arranged on the longer arm of a lever with theconnection to the cutter on the shorter arm so as to transmit greateroperative force to the cutter. To secure this eifect the laminated coreindicated as a whole at 10 is reversed so that the three pole pieces H,12 and 13 are at the lower ends of the casing 14, which casing is alsocomposed of two sections 15 a d 16 separable at the longitudinal line ofthe casing. This casing is also preferably made of a phenoliccondensation product as Bakelite so that it is electrically insulatingand is moisture proof. With the arrangement of the pole pieces as shownit will be noted that they are at the opposite end of the casing from'the cutter head I. Extending over and operated by the magnetic effectof these pole pieces is an armature 11 carried by lever arms 18, one oneach side of the core and inturned at their lower ends as shown at 19 onwhich the armature is mounted by any suitable means such as screws 80.The lever arms I8 are pivotally mounted at 8| on a transverse support 82extending through a passage 83 in the center pole of core and carried bydownwardly extending ears 84 in supporting plates 85 mounted on theopposite sides of the laminated core at the upper ends thereof. Theseplates and the core are bound together and mounted in the casing bytransverse bolts 86 which extend through openings in the casing sectionsI5 and "I6 and in bosses or lugs 81 on the inner walls of thesesections. These bosses have recesses 88 at their inner end to receivethe clamping nuts 89. Thus the laminations and the supporting plates 85may be clamped together by the clamps 89 and then, after assembling, theunit mounted by placing the casing sections in position with the freeends of the bolts extending through the openings in the lugs 87, and canbe clamped to the casing by the nuts 98.

The lever arms I8 are preferably in one piece or in substantiallyinverted U-shape, and they are connected at their upper ends by atransverse piece 9 I. This lever is connected to the projecting end 26of the driving pin for the cutter I8 by the spring arm 92 connected tothe upper portion of one of the lever arms I8 above the pivots 8| asindicated at 93. This spring arm acts the same as the spring arm 23 inthe first form to reciprocate the cutter and to tend to force it towardand hold it closely against the underside of the guard teeth I 6 of thecutter head. The pivots 8| may be of any suitable type but preferably ofheaded pins as shown passing through the arms I8 and into a longitudinalpassage 94 in the element 82. It will be evident that as the pivot 8| isconsiderably nearer to the connection to the cutter than it is to thearmature II this armature has considerable leverage advantage to applygreater driving force to the cutter.

The armature and the levers 18 are normally held in the neutral orcentral position by two coil springs 95 connected to the center of thearmature by a pin 96. At their opposite ends the springs are connectedto studs 91 on a supporting plate 98 clamped against the sides of thepole pieces and to the casing by bolts 99 passing transversely throughthis plate and another plate IIIII on the opposite sides of the polepieces, and to which pole pieces the plates are secured by nuts I8| onthe bolts 99. When assembled in the casing the free ends of these bolts99 extend into openings I02 through bosses I03 on the inner walls of thecasing sections, which bosses have recesses I84 for the nuts IIJI, andthen the whole is clamped to the casing sections by nuts I05 in recessesin the outer walls of the casing, and it will be seen that with thesebolts 99 and the bolts 86 the whole mechanism is securely and firmlymounted in the casing. The laminations of the core and the plates 98 andI may all be clamped together by transverse rivets IIlIS passing throughthe plates and the pole sections II and I2 of the laminations. One ofthe laminations is shown in Fig. 23 and as will be seen the central polesection 13 is divided for the greater portion of its length by a slot13a making a central pole really a double pole.

- The lead cord 65 leading to the operating coils I91 and I08 is mountedin the lower end of the casing the same as shown in Fig. 1 as is alsothe loop 68 for hanging the device on a hook or other suitable support.

Various wiring arrangements of the electrical operating devices whichcan be used are illustrated in the wiring diagrams of Figs. 31 to 34. Inthe wiring diagram of Fig. 31 there is a coil on each of the pole piecesor legs of the core, coil 40 being on the pole or leg 31, coil 4I on thepole or leg 38, and the central coil 42 on the central pole or leg 39.This central coil 42 is in reality a double coil or in two sectionsbecause the lead I09 from the upper end ofthe coil 4| is connected tothe center thereof as indicated at I ID. The lower end of the coil 40 isconnected to the lower end of the coil 4| by a wire III, and the upperend of coil 40 is connected by the lead II2 to one side II3 of analternating current supply. The other side of this alternating currentsupply is connected between two rectifier elements I I and I I8, whichmay be a single rectifier unit preferably of the cupric oxide type andthe lead I I4 connected to the center plate of this unit. The outletfrom the rectifier H8 is connected by a lead II8 to the upper end of thecoil 42 while the lower end of coil 42 is connected by a lead III to theinlet side of the rectifier II5. It will be seen from this arrangementthat the central pole 39 is always of the same polarity while the otherpoles 31' and 38 are alternatively of a different polarity, and when theflux of the pole 31 is zero that in 38 is at a. maximum and vice versa.The three coils 4|], 4| and 42 in the arrangement illustrated are allwound in the same direction, and in view of the various connectionscertain of them have different effects at different times. Thus forexample for one-half of a cycle of the A. 0., supply current is enteringthrough the lead H4 and it cannot pass through the rectifier II5 but canpass through the rectifier IIS and by lead M8 to the upper end of coil42 and out through lead I09 to the upper end of coil 4|, then from thelower end of this coil through the lead III to the lower end of the coil48 and out the upper end thereof back to the other side II3 of the lineor A. C. supply. Thus if we assume that during this half cycle thecenter pole 39 is north because of the excitation by the upper half ofcoil 42 then the two poles 31 and 38 would be of south polarity, and theexcitation by coil 4| would be of north polarity and that would cancelor suppress the south polarity of pole 38, while the excitation of coil49 would be of south polarity and would therefore add to or build up thesouth polarity of pole 31, and the armature 43 will be shifted in onedirection toward the pole 31. Now in the other half of the cycle currentwill flow in through the. lead II2 to the upper end of the coil 40, fromthe lower end of this coil through the lead III to the lower end of thecoil 4| by lead I09 from the upper end of this coil to the center ofcoil 42 and through the lower half of this coil to the lead III andthrough rectifier II5 to the other half N4 of the line or A. C. supply.As before, the central leg 39 is still of north polarity while thepolarities of coils 40 and 4| are now reversed so that 31 is now ofminirr um polarity (coil 40 being now north) and the south polarity of38 has now been built up or added to by the south polarity of coil 4| sothat it is now of maximum polarity. This is because the excitation ofcoil 48 is now of north polarity and suppresses or cancels out the southpolarity of pole 31 while the excitation of coil 4| is now south andtherefore adds to or builds up the south polarity of pole 38, and thearmature is shifted in the opposite direction. Thus it will be seen beof north polarity as the coils may be wound to excite the center pole ofsouth polarity so long as it is excited in the same sense during bothhalves of the cycle. with this arrangement of windings and connectionsthe function of the windings 40 and H is to suppress alternately theexcitation'of the outer poles 31 and 38 of the system and while one isbeing suppressed to build up or add to the flux on the other pole.Therefore the armature and the cutter are given one complete back andforth movement or two cutting strokes for each cycle of the electricsupply current and no make or break devices are required. There are alsono rotating elements the rotating motion of which must be converted intoa reciprocating movement. The two halves of coil 42 are therefore D. C.exciting coils' while coils 40 and" are A. C. coils. Only sufllcientspring action is required to hold the armature in the center or intermdiate position.

Referring to Fig. 32, thisfigure shows a different arrangement of coilsand connections for securing the same result. In this arrangement thereare no coils on the center pole 39 butthere are two sets of D. C.exciting coils on the outer legs 31 and 38, the first set beingindicated at H9 and I20 and the second at I2I and I22,

. while the two A. C. coils in series are indicated at I 23 and I24. Asshown the lower end of coil I23 is connected by lead I25 to one side I28of the A. C. supply while the other end of this coil is connected by thelead I21 to the upper end of the coil I24. These coils are'so wound asto excite their respective cores with the same polarity. The lower endof coil I24 is connected by leads I28 and I29 to the lower end of coilI20, theupper end of this coil being connected by lead I30 to the upperend of coil II9 while the lower end of this coil is connected by leadI3I to the outlet side of'the rectifier 32. The lead I28 is alsoconnected to the lower end of coil I22 the upper end of which isconnected by lead I33 to the upper end of coil I2I the lower end ofwhich is connected by lead I34 to the inlet side of the rectiiier I35.nating supply, indicated at I38, is connected between the two rectifiersI32 and I35. The two coils H9 and I20 polarize the outer legs 31 and 38in a different sense, that is one south and one north polarity duringone half of the cycle. The two coils I2I and I22 have the same effect asthe coils H9 and I20 on the next half of the cycle. Therefore, if weassume that during onehalf cycle the current enters through lead I38 itwill pass through rectifier I32 to coil II9 polarizing the leg 31 ofsouth polarity. It will also pass through 0011 I20 polarizing leg 38with north polarity. It will then pass by lead I28 through the coil I24which will tend to polarize theleg 38 with north polarity which adds tothe north polarity of the coil I20. The current then passes through thecoil I 23 to the other lead I28 of the A. C. supply. This polarizes theleg 31 with north polarity which cancels or suppresses the south Thus itwill be seen that The other side of the alterpolarity of the coil II9.Now on the other half of the cycle as current enters from the leg I2811; passes throughthe coil I23 exciting pole 31 with south polarity andpasses through the coil I24 to excite pole 38 with south polarity. Itthen passes through the coils I22 and I2I which excite legs 38 and 31respectively with north and south polarity and out through the rectifierI35 to side I36 0! 'the'supply. In this case the coil I23 has built upor added to the south excitation of coil I2I'whlle coil I24 hascancelled out or suppressed the north excitation of coil I22, which isjust the opposite of the effect on the first half of the cycle.

Another arrangement for securing this effect is shown in Fig. 33 inwhich there is a coil on each of the three legs of the core. Coil I 31is connected to one side I38 of the A. C. supply while at its upper endit is connected by lead I 39 to the upper end of the coil I40 on leg 38which is connected at its lower end at I between the rectifiers I42 andI43. The other side I44 of the A. C. supply is connected between therectifiers I45 and I48. The lower end of the center coil I41 isconnected at I48 between the rectifiers I43 and I48 while the upper endof this center coil is connected by lead I49 between the rectifiers I42and I45. If now we assume that during one half of the cycle currententers through lead I44 to pass through rectifier I45 to the center coil.I41, exciting pole 38 with north polarity (and legs 31 and 38consequently of south polarity), it then passes by connection I48through rectifier I43 to the lower end of coil*I40 tending to excite leg38 with south polarity. It then passes by lead I39 to enter top of coilI31 tending to excite leg 31 with north polarity and passes to the otherside I38 of the line. It will thus be seen that it has built up or addedto the south polarity in the leg 38 due to the excitation of coil I41and it has suppressed or cancelled out the south polarity in the leg 31.On the other half of the cycle current enters from the lead I38 to thelower end of coil I 31 exciting leg 31 with south polarity, passes bylead I39 to the upper end of coil I40 exciting leg 38 with northpolarity and passing through rectifier I42 to the upper end of centercoil I41 exciting the center pole 39 with north polarity the same as on:excitation of leg 38 is suppressed or cancelled out .and that of leg 31added to or built up during one-half of the cycle, and the excitation of31 is suppressed or cancelled out and that of 38 built up on the otherhalf of the cycle.

Still another arrangement is shown in Fig. 34. In this arrangement thereis no coil on the center leg 39. There are two D. C. exciting coils I50and I5I one on each leg 31 and 38, the upper end of I50 being connectedby lead I52 to the upper end of coil I5I. The lower end of I50 isconnected by lead I53 connected between the rectifiers I54 and I55 whilethe lower end of coil I5I is connected by lead I58 between therectifiers I51 and I58. Also, on the legs 31 and 38 are the two A. C.coils I53 and I80 connected at their upper ends by the leads I 8|. Thelower end of coil I59 is connected by lead I82 to one side I83 of the A.C. supply. The lower end of coil I 60 is connected by lead I 84 betweenthe rectlfiers I54 and I51 The other side I85 of the A. C. supply isconnected between the rectiflers I55 and I58.

If we assume now that current enters during one-half cycle from side I65of the A. C. supply it passes through the rectifier I55 to the coil I50and then through the coil I5I, one of which, for example coil I50, iswound to excite pole 31 with south polarity, and the other coil I5I toexcite leg 38 with north polarity. This current then passes through therectifier I51 and lead I64 to the coil I60 which excites leg 38 withnorth polarity. This adds to or builds up the north polarity of coilI5I. The current then passes by lead I6I to coil I59 and by lead I62 tothe other side I63 of the A. C. supply. This excites coil I59 with northpolarity which cancels out or suppresses the south polarity of the coilI50. On the next half of the cycle the current enters from I63 throughlead I62 to coil I59 exciting leg 31 with south polarity, then by leadI6 I to coil I60 exciting leg 38 with south polarity. Then goes by leadI64 to rectifier I54 and by lead I53 to coil I50 which as before excitesleg 31 with southpolarity, and then goes by lead I52 to coil I5I whichalso as before excites leg 38 with north polarity. It then passes bylead I56 through rectifier I58 to the other side I65 of the A. C.supply. During this half of the cycle the south polarity of coil I59builds up or adds to the south polarity of coil I50 while the southpolarity of coil I60 cancels out or suppresses the north polarity ofcoil I5I which is just the opposite of the effect of the first half.

In each one of the examples given it is of course not necessary that thecoils be wound in the directions shown so longas the D. C. coils arewound and connected so as to excite the core in the same direction orwith the same polarity during both halves of the cycle while the A. C.coils are so wound and connected as to suppress the flux in one of theouter legs and build up that in the other leg during one-half of thecycle and then suppress the flux in the second outer leg and build upthe first outer leg during the second half of the cycle, or merely toalternately suppress the flux in the two outer legs during the twohalves of the cycle.

It is preferred in each arrangement to surround the center pole or legwith a copper tube 39!! to sustain the fiux and reduce stresses on therectifiers. It prevents the field from collapsing between impulses andso protects the exciter windings from voltage stresses.

The rectifiers, that is the two rectifiers H5 and H6 of Fig. 31 and therectifiers I32 and I34 of Fig. 32 may be mounted in the plug-in devicefor connecting the shaver to an outlet receptacle or a lighting socketof a house wiring system, as shown in Figs. 24 to 30. The same devicecan be used for mounting the four rectifiers of Figs. 33 and 34, itbeing only necessary to add the two additional rectifiers in the properrelation as indicated in the diagrams of Figs. 33 and 34. In eachinstance there are two contact blades I66 and I61 projecting from oneend of the plug-in device which when inserted in an outlet receptacle inthe usual manner connect the device with the house wiring system, or,that is, the A. C. current supply. Also, in each instance there arethree leads extending from this plug-in device to the coils in theshaving device. We will assume for illustration that blade I66represents the side I I3 of the A. C. supply. In the arrangement of Fig.31 it is connected in the plug-in device to lead II2 which leads to thecoil 40. This blade includes an enlarged central portion I68 providedwith a lug I69 to which the lead II 2 is soldered.

A plate I10 is insulated from the blade I 68 by insulation HI and tothis plate I10 is connected the lead II 1 leading to the lower end'ofcoil 42. The other blade I61 is offset so as to be connected to acentral plate I12 and on the opposite side of this plate I12 from theplate I10 is a third plate I13 connected to the lead I I8 from the topend of coil 42. Between plates I13 and I12 is the rectifier 6, whilebetween the plate I12 and the plate I10 is the rectifier II5, theserectifiers being preferably of the usual dry plate rectifier of thecupric oxide type which as is well known permits current to pass in onedirection but prevents it from passing in the opposite direction. Thus Ihave shown the rectifiers as each composed of two copper plates I14 eachtreated on one side with the oxide, separated by a lead wash-er I15against the oxide side to give better electrical contact. All of theplates with the blades I66 and I61 may be assembled and clamped togetheras a unit by a central bolt I16, the plates being insulated from eachother and this bolt by an insulating sleeve I11. The blade I66 may alsobe insulated by an insulating washer I18 between it and the nut or headI 19 of the bolt, with a similar insulating washer I at the oppositeside. The Whole device may then be mounted in a casing of moldedinsulating material, preferably a' phenolic condensation product, suchas "Bakelite; The casing shown is in two sections I BI and I32 providedwith recesses I83 to receive the head and nut of the bolt to hold theassembled rectifier unit in proper location in the casing and forcompactness, the sections being secured together by transverse bolts I84and I85. Bolt I85 also preferably passes through lugs or bosses I86extending from the inner walls of the two side sections so that the boltis thoroughly insulated. At the upper end the casing has an opening forthe cord I81 carrying the three leads II2, II 1 and H8, and this openinghas ribs I 88 to grip the rubber covering of the cord so as to take anypulling strain on the cord off the connections of the leads to therectifier plates, and thus prevent these connections being broken by apull on the cord.

Having thus set forth the nature of my invention, what I claim is:

1. In a device of the character described, a cutter head comprising abody having a longitudinal passage adjacent one edge with a longitudinalslot in said edge communicating with said passage, the opposite edges ofsaid slot comprising closely spaced guard teeth extending transverselyof the slot, a cutter in said passage having two rows of cutter teeth atthe inner sides of the guard teeth to cooperate therewith, and means forreciprocating the cutter in a direction longitudinally of the slot.

2. In a device of the character described, two spaced cutting deviceseach comprising a set of spaced guard teeth and a set of cutter teethcooperating therewith, said cutting devices being arranged in oppositionto each other and facing in opposite directions, and means forreciprocating the cutter teeth in a direction transversely of the guardteeth.

3. In a device of the character described, a cutter head comprising abody having at one and two spaced rows of guard teeth facing in oppositedirections with the free ends of said teeth toward each other, aseparate set of cutter teeth cooperatirfg with each row of guard teeth,said two sets of cutter teeth being spaced from each other with the freeends of the teeth in each set toward the other satiand means forreciproeating the cutter teeth in a direction transversely of the guardteeth.

4. In a device of the character described, two spaced cutting deviceseach comprising a set of guard teeth and a set of cutter teeth, saiddevices being arranged so that the free ends of the teeth face inopposite directions and toward each other so that as the device is movedback and forth with the guard teeth against a surface each setalternately acts as a guide for the other set to hold it at the properangle for cutting, and means for reciprocating the cutter teeth in adirection transversely of the guard teeth.

5. In a device of the character described, a cutter head comprising abody having a longitudinal passage adjacent one edge and a longitudina'lslot in one edge leading to the passage, transverse guard teeth on eachedge of the slot, a. reciprocable cutter in the passage having aneccentric longitudinal passage therein and a slot leading therefrom inalignment with the first slot, the edges of said slot in the cutterbeing provided with transverse cutter teeth cooperating with the guardteeth, and means for longitudinally reciprocating the cutter.

6. In a device of the character described, a cutter head comprising abody having a curved edge having a longitudinal slot, opposed cuttingdevices at the opposite sides of this slot and facing each other, eachdevice including a row of guide teeth at the edge of the slot, areciprocable cutter having two spaced rows of cutter teeth one row oneach side of the slot cooperating with the guard teeth, and means forreciprocating the cutter in a direction longitudinally of the slot.

7. In a device of the character described, a cutter head including abody having a curved edge and a cylindrical passage adjacent said edge,said edge having a longitudinal slot communicating with said passageprovided with a series of guide teeth in the opposite edges thereof, acylindrical cutter in said passage having an eccentric passage and aslot leading therefrom in alignment with the first slot and providedwith cutting teeth on the edges of the second slot cooperating with theguard teeth, a guide passage in the head parallel with the first passageand spaced therefrom on the opposite side of the cutter from the slot, aguide plunger reciprocable in the latter passage, and an operating pinfor the cutter connected with the cutter and the guide plunger so thatthe plunger keeps the cutter in alignment with the guard teeth.

8. In a device of the character described, a cutter head including abody having a longitudinal cylindrical passage adi n one edge, and asecond longitudinal passage spaced from the first passage, a cylindricalcutter reciprocable in the first passage, said cutter and body havingaligned slots having opposite edges and provided on these opposite edgeswith cooperating cutting and guard teeth respectively, a guide plungerreciprocable in the second passage, and a connection froin the cutter tothe plunger so that the plunger prevents the cutter from turning in itspassage.

9. In a hair clipper, a skin contacting member, adapted to be passedover the skin for clipping hair therefrom, said member provided withsets of opposed teeth extending toward but not reaching each other andseparated by slots and a cutter provided with sets of similarly opposedteeth and operating adjacent the member and cooperating therewith toclip hair from the skin as the clipper is passed thereover.

10. In a device of the character described, a circumferentially slottedhousing, a circumferentially slotted cutter member cooperatingtherewith, said housing and member having longitudinal channels disposedthereon transversely of and intersecting the said slots.

11. A device of the character described comprising a housing having atransversely curved portion provided with opposed teeth extending towardbut not reaching each other, a cutter adjacent the housing and havingsimilarly opposed teeth to cooperate with the housing teeth in cuttingand means for operating the cutter.

12. In a hair clipper, a housing having a plurality of opposed by slotsand provided with a channel arranged thereon transversely of the saidslots to accommodate hair independently of its length to thereby presentthe hair to the slots as the hair clipper is passed over the skin, acutter member ar-'- ranged adjacent the housing and means for oper-%ating the cutter 'member in relation to the hoiis ing.

13. In a hair clipper, a housing slotted to provide a plurality ofopposed parallel spaced teeth separated by the slots, said housingprovided with a channel arranged thereon transversely of said housingslots to accommodate the hair independently of its length to therebypresent the hair to the slots as the hair clipper is passed over theskin, a cutter member arranged adjacent the housing and similarlyslotted and channelled and means for operating the cutter member inrelation to the housing.

THOMAS J. MURPHY.

.Patent No. 2,1l 6,6b,5.

' February 7, 1959.

THOMAS J. MURPHY. It is hereby certified that error appears in theprinted specification of the above numbered patent requiring correctionas follows: column, line 17, claim 5, for the word "one" read said;

Page 7, first and that the said Letters Patent should be read with thiscorrection therein that the 88.1118 may conform to the record of thecase in the Patent Office.

Signed and sealed this 5th day of September, A. D. 1959.

(Seal) Henry Van Arsdale, Acting Commissioner of Patents.

